Where can I buy a box of Duel terminal cards?

I've heard about the Turbo box, but I'm looking for the most recent set. I have a little money to spend around the vicinity of 50-70 dollars. How many cards come in the box anyways? and does the box come with individual Packs? Where can I buy the packs? I heard the boxes range from 250-750 dollars. I don't want to pay that much. For the critisicers these cards can be sold for more than 3$ each, so multiply that times the number of cards in the box and you have yourself a worthy investment (maybe O.o)